Aminoalkyl hydroxylamines as photographic developers



United States Patent 3,287,125 AMINOALKYL HYDROXYLAMINES AS PHOTOGRAPHIC DEVELOPERS Milton Green, Newton Highlands, Mass., and Adnan A. Sayigh, North Haven, and Henri Ulrich, Northford, Conn., assignors to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed June 26, 1963, Ser. No. 290,618 15 Claims. (Cl. 96-29) This invention relates to photography and more particularly to novel chemical compounds usefiul in the development of photosensitive silver halide elements.

It is one object of the present invention to provide novel chemical compounds which may be employed in the development of silver halide emulsions.

Another object of the present invention is to provide novel developer compositions and processes employing such novel developer compositions for the development of silver halide emulsions.

A fiurther object of this invention is to provide novel developer compositions usetul in diffusion transfer processes.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the compositions possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will. be indicated in the claims.

Other objects of this invention will in part be obvious and will in part appear hereinafter.

The present invention relates to novel N-substit-uted hydroxylamines corresponding to the zforrnula:

R -N-R wherein at least one of R and R is an alkyl group containing an intralinear amino nitrogen atom, either cyclic or acyclic, and the other of R and R is selected from the group consisting of alkyl groups and alkyl groups containing an intralinear amino nitrogen atom, either cyclic or acyclic. R and R preferably contain from 1 to 7 carbons, but may contain more carbons provided the resulting compound is soluble in aqueous sodium hydroxide.

The preferred hydroxylamines of this invention include:

(1) OH CH 0 H I IC Hz-C H2 I C H 'NmethylN-2-dimethy1aminoethykhydroxylamine 0 BAH: Ear X N-methyl-N- (N-morpl1o1ino) methyl-hydroxylamine O H -bI-C H2O Evil-NH:

N-rne thyl-N-2-carboxamid oethyl-hydroxylamine [-3- (iN-methyl) -hydroxylaminopropionamide] CH l ICHzOH N N-methyl-N-2- (2-pyridyl) ethyl-hydroxylamine N ,N-bis-[2-'(4 -pyridyl) -ethyl] hydroxylamine The use of hydroxylamines in developing silver halide emulsions is disclosed, e.'g., by Land et al., US. Patents Nos. 2,857,274; 2,857,275; and 2,857,276. A particularly useful :hydroxylamine has been N,N-diethy-lhydroxylamine. The novel chemical compounds of the present invention exhibit many properties making them more desirable as silver halide developing agents than hydroxylamines previously used, as will be noted hereinafter.

Many of the novel hydroxylamines of this invention may be prepared by an addition reaction ibetween a hydroxylamine and an appropriate compound, mg, a pyridine or acrylamide, containing an activated double bond. Where the reaction is exothermic, use of cooling means, e.g., addition of ice, may be desirable to hold the to perature below the critical point. Isolation of the product preferably is accomplished by vacuum fractionatiug or by recrystallization of a suitable solvent, though in some cases extraction or other purification procedures may be desirable before distillation.

The following detailed examples are given only to illustrate the preparation of preferred compounds the scope of this invention, and are not intended to be in any Way limiting.

Example 1 A flask was charged with 72 g. (0.5 mole) of dimethyl aminoethylchloride hydrochloride and 41.75 :g. (0.5 mole) of N-methylhydroxylamine hydrochloride in 300 cc. of methanol. 53 g. (0.5 mole) of sodium bicarbonate in ml. of water was added gradually to the mixture in the flask. The reaction mixture was refluxed for 4 hours, after which the inonganic salts were filtered off, the filtrate evaporated. Extraction of the residue with chloroform gave 14 :g. (18.2% yield) of Nmethyl-N-Z-dimethylamino ethyl-hydroxylamine hydrochloride melting at 126- 127 C. Sodium hydroxide was added to the water layer and extraction with chloroform gave 11 g. (18.7%) of the free amine, boiling at 43 C. at a pressure of 0.5 mm. Elemental analysis of the hydrochloride gave the following results:

Calculated cfor C H ClN O: Percent C, 38.83; percent H, 9.77; percent N, 18.11. Found: percent C, 39.10; percent H, 9.85; percent N, 18.28.

Example 2 To a flask charged with 15.7 g. of methylhydroxylamine hydrochloride suspended in 32.8 g. of morpholine, 15 g. of 37% formaldehyde was added dropwise with stirring and ice cooling. During the addition the reaction mixture became homogeneous and after stirring for about 30 minutes no formaldehyde odor could be noted. After standing, the top oily layer of the reaction mixture was removed and vacuum distilled to yield 8.4 g. (31% yield) of the desired N-methyl-N-(N'unorpholino)-methyl-hydroxylamine as a colorless oil easily soluble in 5% NaOH and boiling at 60-65" C. at a pressure of 1 Nitrogen analysis of the product gave 19.0% compared with the calculated value of 191% for c -H N O Example 3 To 20 g. of N-methylhydroxylamine hydrochloride in cc. of methanol, 7 g. of anhydrous sodium carbonate and 14.2 g. of acrylamide were added with stirring.

After 5 minutes a slight exothermic reaction was observed. The reaction mixture was refluxed for 30 minutes, filtered, and the filtrate was evaporated in vacuo.

Recrystallization of the crude crystalline residue gave.

14.3 g. (60.5% yield) of N-methyl-N-Z-carboxamidoethyl-hydroxylamine product, melting at 94-95 C. The infrared spectrum (KBr) showed major bands at 3.03 (NH); 3.18 (OH); 5.98 (CO); 695 Nitrogen analysis of the product gave 23.41% compared with the calculated f! C H N O Example 4 A 36.75 g. (0.35 mole) portion of 2-vinylpyridine was added dropwise, with cooling, to 41.75 g. (0.5 mole) of N-methyLhydroxylamine hydrochloride. The reaction mixture was stirred at room temperature and an exothermic reaction took place causing the temperature to rise to 50' C. After stirring for 3 0 minutes at 50 C., aqueous sodium carbonate was added and the alkaline reaction mixture was extracted with chloroform. Rectification in vacuo gave 41.8 g. (79% yield) of N-methyl-N-2-(2'-pyridyl)-ethyl-hydroxylamine boiling at 95- 97 C. at a pressure of 0.15 mm. Elemental analysis of the methiodide, melting at 113-1 14 C., gave:

Calculated for C H N O: Percent C, 36.73; percent H, 5.13; percent N, 9.52. Found: Percent C, 36.88; percent H, 5.41; percent N, 9.82.

Example 10.5 g. of 2-vinylpyridine were added in one portion to 3.45 g. of hydroxy-lamine hydrochloride in 40 cc. of Warm methanol, and the reaction mixture was refluxed for 10 minutes and allowed to stand overnight. 3 g. of sodium carbonate and a few drops of water were added with stirring. The reaction mixture was filtered andthe filtrate was evaporated. Recrystallization of the residue from benzene gave 6.9 g. (57% yield) of N,Nbis-[2- (2'pyridyl)-ethyl]-hydroxylamine melting at 110-111 C. Nitrogen analysis gave 17.26% compared with 17.27% calculated for C14H17N3O.

Example 6 N methyl-N-2- (4-pyridyl) ethyl-hydroxylamine was synthesized from 36.75 g. (0.35 mole) of 4-vinylpyridine and 41.75 g. (0.5 mole) of N-methylhydroxylamine hydrochloride in a manner similar to that set forth in Example 4. The crude product was purified by dissolving it in hot benzene and adding ligroin until a turbidity was observed. 36.8 g. (69.5% yield) of pale yellow crystals were obtained. After further recrystallization from ligroin, the product melted at 78 C., and gave the following elemental analysis:

Calculated for C H N O: Percent C, 63.13; percent H, 7.95; percent N, 18.41. Found: percent C, 63.24; percent H, 8.05; percent N, 18.10.

Example 7 N,N-bis-[2-(4'-pyridyl) -ethy1] -hydroxylamine was synthesized from 36.75 g. (0.35 mole) of 4-vinylpyridine and 34.75 g. (0.5 mole) of hydroxylamine hydrochloride in a manner similar to that set forth in Example 5. The solid reaction product was recrystallized from benzene to give white needles melting at 148-149- C.

As previously mentioned, the novel silver halide developing agents of this invention are useful in conventional or wet development of silver halide emulsions, diffusion transfer processes, both dye and silver, and many of them are especially useful in such photographic processes wherein it is desired to eliminate or minimize the need for washing or stabilizing operations in liquid baths subsequent to the formation of the silver print. Examples of such processes are disclosed in US. Patent No. 2,647,056 to Edwin H. Land.

In diffusion transfer processes of this type, as is well known in the art, an exposed .silver halide emulsion is treated with a liquid processing composition while in superposed relationship with an image-receiving mate-. The liquid processing composition develops exposed silver halide to silver and reacts with unexposed rial.

silver halide to form a complex silver salt which is transferred to the image-receiving material and there reduced 1 to silver to form a positive print. The processing composition includes a silver halide solvent, such as sodium thiosulfate, and may also contain a film-forming mate rial for increasing the viscosity of the composition. As used herein, the term silver halide solven refers to reagents which will form a soluble complex with silver. halide, as is well known in the art of forming silver images .by transfer.

The following example is intended to illustrate the use of the novel developing agents of this invention in diffusion transfer processes, and is intended to, be illus-' trative only.

Example 8 A silver iodobromide emulsion sold .by E. I du Pont de Nemours & Co., Wilmington, Delaware, was exposed and processed with a processing solution preparedby.

adding 0.4 g. of N-methyl-N-2-dimethylaminoethyl-hydroxylamine to 10 cc. of a composition comprising:

Sodium carboxymethyl cellulose g 38.1 Sodium hydroxide g 34.2 6-nitrobenzimidazole nitrate g 60 Sodium sulfite g 53.6 Sodium thiosulfate g 20.0 Water cc 850 The image-receiving element comprised a silver-receptive stratum containing silver-precipitating nuclei dispersed .in

molar equivalents of the other novel hydroxylamines prepared in the above examples also gave good diffusion transfer images.

N,N-diethyl-hydroxylamine is characterized by substantial volatility at room temperatures. While this is a desirable property. for many purposes, e.g., to remove unreacted developing agent without washing operations,

there results a strong fishy. or amine odor which is objectionable in many applications, e.g., where a number of prints are to be made in a short time in the same room. In contrast, many'of the novel developing agents of this invention do not exhibit strong odors at room temperature because their vapor pressures are appreciably lower than that of N,N-diethy1-hydroxylamine. Although N-methyl- N-2-dimethylaminoethylhydroxyl-amine does have appreciable volatility at room temperature, ithas a shorter development induction period than N;N-diethyl-hydroxylamine. The compounds containing a heterocyclic nitrogen atom may be less desirablethan the others in certain applications, since they tend to form coloredoxidation products instead of the colorless or substantially colorless oxidation products of the other compounds.

The induction periods of the novel developing agents of this invention were tested by applying an approximately 1 molar solution of the hydroxylarnine in 5% sodium hydroxide to a fogged silver iodobromide emulsion and 1 noting the elapsed time before strong developing starts.

The compounds preparedin Examples 1, 4, 5 and 6 all showed induction periods of from 1 to 2 seconds, and that of Example 3 showed an induction period of 3 seconds, as compared with 2.5 to 3 seconds for N,N-diethyl-hydroxylamine and 8 seconds for N,N-dimethyl-hydroxylamine.

The novel developing agents may be employed in solution or they may be initially incorporated in a layer of the photosensitive or image-receiving elements; in the latter case they are preferably employed as acid salts, e.g., as the hydrochloride or hydrobromide.

It will be apparent that the relative proportions of the novel developing agents of the developer compositions set forth above may be varied to suit the requirements of the operator. Thus, it is within the scope of this invention to modify the above developer compositions by the substitution of preservatives, alkalies, silver halide solvents, anti-foggants, etc., other than those specifically mentioned. Where desirable, it is also contemplated to include in the developer composition common components such as restrainers, accelerators, etc.

Since certain changes may be made in the above compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. As a new developer composition, an aqueous solution comprising an alkaline material, a silver halide solvent, and a silver halide developing agent selected from the group consisting of compounds within the formula:

wherein at least one of R and R is selected from the group consisting of alkyl groups containing an intralinear amino nitrogen atom, and the other of said R and R is selected from the group consisting of alkyl groups and alkyl groups containing an intralinear amino nitrogen atom.

2. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion with an aqueous solution comprising an alkaline material and a silver halide developing agent selected from the group consisting of compounds represented b the formula:

wherein at least one of R and R is selected from the group consisting of alkyl groups containing an intralinear amino nitrogen atom, and the other of said R and R is selected from the group consisting of alkyl groups and alkyl groups containing an intralinear amino nitrogen atom.

3. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion with an aqueous solution comprising an alkaline material and N-methyl-N-2-dimethylaminoethyl-hydroxylamine for a suflicient time to develop said exposed silver halide emulsion.

4. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion with an aqueous solution comprising an alkaline material and N-methyl-N-(N'-m0rpholino)-methyl-hydroxylamine for a sufficient time to develop said exposed silver halide emulsion.

5. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion with an aqueous solution comprising an alkaline material and N-methyl-N-Z-carboxamidoethyl-hydroxylamine for a suficient time to develop said exposed silver halide emulsion.

6. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emul- 5 sion with an aqueous solution comprising an alkaline material and Namethyl-N-Z-(Z-pyridyl)ethyl-hydroxylamine for a sufiicient time to develop said exposed silver halide emulsion.

7. A method of developing a silver halide emulsion 10 which comprises treating an exposed silver halide emulsion with an aqueous solution comprising an alkaline material and N,N bis-[2-(2'-pyridyl) -ethyl] -hydroxylamine for a suflioient time to develop said exposed silver halide emulsion.

8. A photographic process comprising the steps of developing an exposed silver halide emulsion with an aqueous alkaline solution comprising a silver halide develop ing agent and a silver halide solvent in the presence of an image-receiving material superposed on said silver halide emulsion, said developing agent being selected from the goup consisting of compounds represented by the formula:

IRA-N-R wherein at least one of R and R is selected from the group consisting of alkyl groups containing an intralinear amino nitrogen atom, and the other of said R and R is selected from the group consisting of alkyl groups and alkyl groups containing an intralinear amino nitrogen atom to form a positive silver print on said image-receiving material.

9. A process as defined in claim 8, wherein said developing agent is N-methyl-N-Z-dimethylaminoethyl-hydroxylamine.

10. A process as defined in claim 8, wherein saiddeveloping agent is N-methyl-N-(N'-morpholino)-methy1- hydroxylamine.

11. A process as defined in claim 8, wherein said developing agent is N-methyl-N-Z-carboxamidoethyl-hydroxylamine.

12. A process as defined in claim 8, wherein said developing agent is N-rnethyl-N-2-(2-pyridyl) ethyl-hydroxylamine.

13. A process as defined in claim 8, wherein said developing agent is N,N- bis- [2-(2'-pyridyl)-ethyl] -hydroxylamine.

14. A process as defined in claim 8, wherein said developing agent is N-methyl-N-2-(4-pyridy-l)-ethyl-hydroxylamine.

15. A process as defined in claim 8, wherein said developing agent is N,N-bis- [2- (4'-pyridyl) -ethyl] -hydroxylamine.

References Cited by the Examiner UNITED STATES PATENTS 2,169,976 8/1939 Guenther 260-583 2,857,276 10/ 1958 Land et a1. 9629 3,137,705 6/ 1964 Prelog et a1 260583 X OTHER REFERENCES Agwada: J. Org. Chem, vol. 7, 1962., pp. 3153-3155. Reich et 21.: J. Amer. Chem. Soc., vol. 77, pp. 5434- 5436 NORMAN G. TORCHIN, Primary Examiner.

DONALD LEVY, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,287,125 November 22, 1966 Milton Green et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 25, for "C H N O" read CgH15IN2O column 4, line 28, for "60" read 6.0

Signed and sealed this 28th day of November 1967.

(SEAL) Attest:

EDWARD J. BRENNER EDWARD M. FLETCHER,JR. Attesting Officer Commissioner of Patents 

1. AS A NEW DEVELOPER COMPOSITION, AN AQUEOUS SOLUTION COMPRISING AN ALKALINE MATERIAL, A SILVER HALIDE SOLVENT, AND A SILVER HALIDE DEVELOPING AGENT SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS WITHIN THE FORMULA: 